THOUSANDS of Nigerian opposition supporters have protested at the outcome of their country’s presidential election as calls for a rerun of the ballot intensify.

Dressed in black and holding signs, the demonstrators, led by second-placed candidate Atiku Abubakar of the People’s Democratic Party, marched on Monday to the headquarters of Nigeria’s Independent National Electoral Commission in the capital Abuja.

Once there, they blocked the entrance as they demanded a new election under conditions that would ensure accurate results.

“The provisions of the current electoral law have been completely contravened,” said Mr Abubakar. “This protest is going to continue for a very long time.”

At least five political parties are challenging last month’s vote, alleging that delays in uploading results from Nigeria’s 177,000 polling stations to the electoral commission’s portal could have allowed ballot tampering.

They also say that voter intimidation and suppression took place.

Bola Tinubu of the All Progressives Congress won the election with 37 per cent of the votes cast, becoming Nigeria’s first presidential candidate to win with less than half the total.

The election result can only be overturned if it is proven that the electoral commission largely failed to respect the law and acted in ways that could have changed the result.

The conduct of the presidential election has also been criticised by some foreign observers.

US ambassador Mary Beth Leonard said that the balloting process failed to meet Nigerians’ expectations after years of improvement in the quality of elections.

“We thus reiterate our call on [the electoral commission] to address promptly the challenges that can be resolved ahead of the March 11 gubernatorial elections,” she said in a statement on Sunday.

Last Friday, a court granted both Mr Abubakar and third-placed contender Peter Obi permission to inspect the election materials used in the vote as part of their court challenge.